<template>
    <div class="todo-footer" v-show="total">
        <label>
          <input type="checkbox" :checked="isAll" @click="checkAll"/>
        </label>
        <span>
          <span>已完成{{doneTotal}}</span> / 全部{{total}}
        </span>
        <button class="btn btn-danger" @click="clearAll()">清除已完成任务</button>
    </div>
</template>

<script>
export default {
    name:'MyFooter',
    props:['todos','checkAllTodo','clearAllTodo'],
    computed:{
      total(){
        return this.todos.length
      },
      doneTotal(){
        return this.todos.reduce((pre,current)=>{
          return pre+(current.done?1:0)
        },0)
      },
      isAll(){
        return this.total === this.doneTotal && this.total > 0
      }
    },
    methods:{
      checkAll(e){
        this.checkAllTodo(e.target.checked)
      },
      clearAll(){
        this.clearAllTodo()
      }
    }
}
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>